This document describes purpose and usage of a Natural global buffer pool (GBP) under the operating system BS2000.
In the examples below, the notation vrs or vr represents the relevant product version. For further information on product versions, see Version in the Glossary.
The section covers the following topics:
The Natural global buffer pool is a common memory pool that can be used with BS2000 Version 10.0 and above.
On XS31 computers, it can be located either below 16 MB or in the extended address space above 16 MB. On non-XS31 computers, it can be located in the user address space below Class 4 storage (whose size depends on how the operating system was generated).
The global buffer pool can be used by several Natural under TIAM, Natural under openUTM and batch applications simultaneously. It is possible to have more than one global buffer pool per operating system.
The global buffer pool has to be activated before the first Natural application is started. It can remain active as long as the operating system is active, even after the last Natural session has been terminated. This means that the global buffer pool's contents are still available when a new session is started and need not be loaded into the buffer pool again.
The global buffer pool is established by executing a batch job which starts the program CMPSTART. The global buffer pool's name, size, virtual address, etc. are determined by parameters specified in this job.
Example of CMPSTART Job:
/SYSFILE SYSOUT.LST.BPvrsGA /SYSFILE SYSDTA=(SYSCMD) /EXEC (CMPSTART,$NATvrs.NATvrs.BS2.MOD) NAME=BPvrsGA,TYPE=NAT,POSI=ABOVE,SIZE=2MB,ADDR=260,PFIX=NO,SCOP=GLOBAL /SYSFILE SYSDTA=(PRIMARY)
If the parameter values are invalid or do not match the BS2000
environment, the buffer pool task is terminated with an error message. The
error message contains the reason for the termination and (if applicable) the
SVC return code. All error messages are output on
SYSOUT. In the
case of grave errors, they are also displayed on the operator console.
Once the global buffer pool is active, it is administered via the operator console.
The following BS2000 console commands are available:
||Displays the current parameters settings and the start time of the global buffer pool.|
||Terminates the buffer pool task normally.|
||Terminates the buffer pool task abnormally and produces a dump.|
Where tsn is the TSN of the buffer pool task.
The termination of the buffer pool task does not necessarily mean the termination of the global buffer pool, as the common memory pool remains active until the end of the last Natural application.
You can also terminate global buffer pools by executing the
CMPEND program, for example:
/PROC C /SYSFILE SYSDTA=(SYSCMD) /EXEC (CMPEND,NATvrs.MOD) name /* name of the global buffer pool /SYSFILE SYSDTA=(PRIMARY) /ENDP